1. Field of the Invention
The present invention relates to molded plastic panels for covering building surfaces.
2. Description of the Related Art
Molded plastic siding panels for exterior building walls are known in the prior art. These molded panels are made from synthetic thermoplastic polymers, including polypropylene, polyethylene, and various mixtures and copolymers thereof.
Laterally elongated molded plastic panels are nailed to a wall support surface in horizontal rows partially overlapping each other in order to provide a pleasing appearance combined with a weather-resistant protective layer over the support surface.
The molded plastic panels are typically installed by securing several adjacent courses to a wall support surface, starting with a bottom course. A lower marginal edge region of each panel in courses above the bottom course overlaps a panel in the course immediately below. Side marginal edge regions of each panel overlap side marginal regions of adjacent panels.
Various mechanisms have been proposed for interlocking lower marginal edge regions of the plastic panels with panels in the course immediately below. Some of these methods include a locking tab extending forwardly and downwardly from the top of each panel, and a return leg extending upwardly and rearwardly from the bottom of each panel. As each panel is installed, the return leg of the panel being installed is interlocked with the locking tab of the panel below it, which has previously been installed. These interlocking components may require difficult and time consuming manufacturing processes.
U.S. Pat. No. 6,224,701, issued to D. A. Bryant, et al. on May 1, 2001, and assigned to the assignee of the present invention, discloses a molded plastic siding panel. This panel is molded with the nail hem formed from two mating components connected by a living hinge, and the locking tab projecting upward from the top of the panel. After molding, the living hinge of the nail hem is folded, and the two opposing components are secured to each other initially by rivets on one half fitting with an openings on the other half. The two halves are then thermally or ultrasonically joined together. While this process has been found to produce a siding panel of high quality and which is easy to install, a simplified manufacturing process, having a reduced number of steps, is desired.